Moebius FS-1 Build

[bigdave]

That is within my power!!

That is within my power!!
This is the impeller the output nozzle/bearing and main housing.
I have been working on the install all morning and am not ashamed to say is taxing my Pea-Brain!!
Very tight garters in there and I have changed my plan of attack about 4 times so far.
I still think I can make it work but it will be tight!!
Hey Steamboy!! If you see clouds of smoke raising in the north it is my head imploding again!! Ha!! BD.

[junglelord]

Hey Big Dave, could you

Hey Big Dave, could you not use one of those, maybe not that size, for a Seaview within a WTC? What do you think?>

[bigdave]

I am not sure I

I am not sure I follow you , but it is not a good idea to have water flowing in and out of the cylinder itself. BD.

[junglelord]

LOL....thats funny, I guess it

LOL....thats funny, I guess it reads that way....LOL.
NO, I meant the same set up, but for a Sub.
Motor in the WTC, Pumpjet external.


Just I was looking at those a few weeks ago, wondering how to make it suitable for a WTC...and you just showed me how....so why not throw one in a larger WTC for a larger model?

I might like to make a Star Trek Enterprise E pumpjet.

[bigdave]

A little more done this

A little more done this morning.
I was able to get the drives to fit flush with the rear bulkhead and clear the bottom of the hull.
I can even get the top of the hull on without the drives hitting. Not by much mind you!!
I will have cradles to hold up the cylinders and the drives will screw to the rear bulkhead.
Looks like I may have JUST enough room to fit the Otter box. If not, I will have to change the design again. BD.

[anonymous]

Nice clean work as usual

Nice clean work as usual BD!

Steve

[tsenecal]

Dave,

I have used those same

Dave,

I have used those same graupner jetpumps in a couple of mini jetboats I have built, and I use the following motor in my boats...

http://www.horizonhobby.com/Products/De ... D=AGNM4375

they are outrunners, with very similar specs to what you have in the FS-1,

except for one thing...

they have an outer can that doesn't rotate, like an inrunner. I am thinking you might be able to fit stuff into the motor WTCs easier if you don't have to worry about keeping the rotating part of the motor clear.

[bigdave]

Would you happen to know

Would you happen to know about how much current you were drawing, and what the shaft diameter and length is? I chose my motor because it was about the same power as a 540, the shaft was 1/8" and was long enough to pass through an end cap. The $20 price did not hurt either.
Well I think it was the A Team that use to say, "I love it when a plan comes together".
I was doing some of my staring at the parts and trying to think of different ways to proceed today and think I figured an easier way to duct the intake water. And I am all about easy.
Instead of coming underneath the cylinders and Otter box I decided to go around in the free flood area. I will even attempt to bring in the water through the real intakes and not the windows as I was thinking. This may cut down on my reverse thrust but as long as it goes in reverse I am good with that.
The white paper template is the area I am thinking of.
I also found out that the Otter Box does in fact fit with the drives in and the top on. Woo Hoo!! BD.

[tsenecal]

dave, I am running them

dave, I am running them with 2000mah 15c lipo batteries and mamba 25 amp ESCs, with no problems, so i am definitely pulling less than 25 amps.

the motors have 1/8th inch shafts that are between 1/2" and 5/8" long.

the motor itself is about the same size as a speed 400 brushed motor, but put out at least as much power as a speed 600 brushed motor.

on a 2 cell lipo the boats do 13 mph (clocked on a GPS) with a 3 cell lipo, the jet pump cavitates.

[bigdave]

Thanks for the info. http://www.subcommittee.com/forum/icon_cool.gif

Thanks for the info.
How big is your jet boat?
I would love to do a PBR with twin jets someday.
They are cool boats!! BD.

[tsenecal]

Dave,

relatively small,

16" x 7",

Dave,

relatively small,

16" x 7", two piece vacform hull & deck

all up weight, ready to run, 19oz.

Tim

[bigdave]

Very nice!! I like it!!


Very nice!! I like it!!
Was that a kit or did you make it yourself? BD.

[bigdave]

I was able to get

I was able to get some more time in on the FS-1 today and things still are looking good.
First thing I did was modify the Otter box latch assembly. The latches that come with the box are too hard to remove and would be near imposable in the boat. So I made up my own design that can be removed easily.
Then I decided before I make the final templates for the ducting I better finish mounting the drive assemblies. I made up some cradles that the cylinders will mount too.
Just a simple tie wrap will hold them in place plus the two rear mounting screws. I had to put the drive units at a slight angle to miss the upper hull where the fins are.
It looks like I will be able to make my ducts up OK but will not know how good they work till I test.
If this intake idea does not work I can always open two in the bottom right under the jet intakes.

I can here Crazy Ivan cringing at the thought of that!!
But my philosophy is I would rather have them run right than look right!! BD.












This is peeking in through the back door.
You can also see the impellers.

[crazy ivan]

BD cogitated I can here

BD cogitated

I can here Crazy Ivan cringing at the thought of that!!
But my philosophy is I would rather have them run right than look right!!

AAGGGGGGGHHHHH!!!!!!! Couldn't you rotate those jets so that the intakes come in from the side, where your proposed ductwork would be? Remember, "It is better to look good than to feel good”. Who said that, eh? Hint: he also said "You Look Marvelous!"

BTW, do those JPs incorporate any anti-swirl stators? Can't really tell from the pixs.

[Larry Kuntz]

Better save a little space

Better save a little space for flotation. You may end up with pontoons attached to make it almost neutral! Looks like a lot of weight in there. Two motors, good size battery.